Medical Image of the Week: Pulmonary Artery Dilation

Figure 1.  Axial section of the thoracic CT scan showing the massively dilated pulmonary trunk and artery.

The upper limit of the normal diameter of the main pulmonary artery on CT scan is 29 mm and of the right interlobar artery is 17 mm (1). A dilated pulmonary artery can arise from a variety of disease states. Most commonly from one of the many causes of pulmonary hypertension including idiopathic, previously termed primary, pulmonary artery hypertension (PAH). Other less common causes of pulmonary arterial dilation include pulmonary valvular stenosis, atrial septal defect, and idiopathic dilatation of the pulmonary artery.

Our patient is 66-year-old man with exertional dyspnea who was found to have a dilated pulmonary artery on thoracic CT scan during his work up (Figure 1).  His case is suspected to be idiopathic dilatation (1). This is a rare disease with estimates around 0.6% of patients with known congenital heart disease. The estimates in the general population are unknown. There have been a few different diagnostic criteria proposed, but most contain the following:

1. Dilation of the pulmonary trunk 
2. Absence of abnormal intracardiac or extracardiac shunts
3. Absence of chronic heart or lung disease
4. Absence of arterial diseases such as syphilis, arteriosclerosis or arteritis
5. Normal pressures in the right ventricle and pulmonary artery

Patients are usually asymptomatic or with minimal symptoms of dyspnea such as our patient. Rarely, it can present dramatically from compression of nearby structures. This includes constriction of the trachea or major branches or sudden cardiac death from compression of the left main coronary artery.

Tiffany Ynosencio MD and Swathy Puthalapattu MD

Division of Pulmonary, Allergy, Critical Care and Sleep

Banner-University Medical Center and Southern Arizona VA Health Care System

Tucson, AZ USA

Reference

1. Malviya A, Jha PK, Kalita JP, Saikia MK, Mishra A. Idiopathic dilatation of pulmonary artery: A review. Indian Heart J. 2017 Jan-Feb;69(1):119-24. [CrossRef] [PubMed]

Cite as: Ynosencio T, Puthalapattu S. Medical image of the week: pulmonary artery dilation. Southwest J Pulm Crit Care. 2018;16(1):46-7. doi: https://doi.org/10.13175/swjpcc012-18 PDF 

November 2017 Imaging Case of the Month

Michael B. Gotway, MD¹

Isabel Mira-Avendano, MD²

¹Mayo Clinic Arizona, Scottsdale AZ USA

²Mayo Clinic Jacksonville, FL USA

Clinical History: A 70-year-old white woman with a remote history of smoking and mild gastroesophageal reflux disease presented with complaints of a dry cough and shortness of breath, present for some time but worsening over the previous 8 months. No hemoptysis was noted and the patient did not complain of chest pain. No history of syncope was noted.

Physical examination was largely unremarkable and the patient’s oxygen saturation was 86% on room air, 90% on 4 L/m by mask. The patient’s vital signs were within normal limits.

Laboratory evaluation was unremarkable.  Quantiferon testing for Mycobacterium tuberculosis was negative, and testing for coccidioidomycosis was unrevealing. Enhanced thoracic CT (Figure 1) was performed.

Figure 1. Panels A-D: Representative static images from the thoracic CT scan in lung windows. Lower panel: Video of thoracic CT scan in lung windows.

Which of the following statements regarding the thoracic CT is most accurate? (Click on the correct answer to proceed to the second of eight pages)

1. The thoracic CT shows advanced destructive emphysema
2. The thoracic CT shows bilateral, basal and subpleural predominant reticulation associated with ground-glass opacity, architectural distortion, and traction bronchiectasis
3. The thoracic CT shows multifocal lobular consolidation
4. The thoracic CT shows multifocal small pulmonary cysts
5. The thoracic CT shows small cavitary pulmonary nodules

Cite as: Gotway MB, Mira-Avendano I. November 2017 imaging case of the month. Southwest J Pulm Crit Care. 2017;15(5):199-208. doi: https://doi.org/10.13175/swjpcc134-17 PDF

July 2015 Imaging Case of the Month

Michael B. Gotway, MD

Department of Radiology 

Mayo Clinic Arizona

Scottsdale, AZ

Clinical History: A 40-year-old woman with a history of left breast malignancy diagnosed 11 years earlier, initially treated with lumpectomy, radiation, and chemotherapy (doxorubicin, cyclophosphamide, paclitaxel, followed by Herceptin), later treated with mastectomy following recurrence 2 years after diagnosis, presented with a several month history of upper respiratory infectious symptoms, including congestion, productive cough, and rhinorrhea. The patient also complained of some fatigue, although she was still active; she denied shortness of breath initially, but claimed that increasing breathlessness had developed more recently, limiting her exercise tolerance. The patient denied gastrointestinal, gynecological, musculoskeletal, or neurological complaints and no weight loss had occurred.

On admission to the hospital, her white blood cell count was mildly elevated at 14 x 10⁹ cells/L, with anemia as well (hemoglobin / hematocrit= 10 gm/dL / 28%, respectively). Her platelet count was also borderline decreased at 183 x 10⁹ cells/L. Electrolyte and liver panels showed normal values.

A frontal chest radiograph (Figure 1) was performed.

Figure 1. Frontal (A) and lateral (B) chest radiography.

Which of the following statements regarding the chest radiograph is most accurate? (Click on the correct answer to proceed to the second of six panels)

1. The frontal chest radiograph shows abnormal mediastinal contours
2. The frontal chest radiograph shows basal predominant fibrotic abnormalities
3. The frontal chest radiograph shows large lung volumes with a cystic appearance
4. The frontal chest radiograph shows mildly enlarged central pulmonary arteries
5. The frontal chest radiograph shows no abnormal findings

Reference as: Gotway MB. July 2015 imaging case of the month. Southwest J Pulm Crit Care. 2015;11(1):26-35. doi: http://dx.doi.org/10.13175/swjpcc090-15 PDF

Medical Image of the Week: Idiopathic Pulmonary Artery Hypertension

Figure 1. EKG showing sinus rhythm, right bundle branch block and peaked ('pulmonary') p waves (arrow).

Figure 2. Two view chest X-ray showing right ventricular hypertrophy (arrows, note filling of the retrosternal space by an enlarged right ventricle in the lateral view) and enlarged central pulmonary arteries (arrowhead).

 

  Figure 3. Axial CT angiogram of the chest below the carina showing dilated pulmonary artery (diameter of pulmonary artery greater than aorta, arrow).

 

Figure 4. Panel A: Parasternal short axis view shows septal bowing to the left, a severely dilated right ventricle and a D-shaped left ventricle. Panel B: Four chamber view shows right atrial and ventricular dilatation.

A 39-year-old woman presented to the clinic with a history of progressive shortness of breath of 6-month duration associated with bilateral lower extremity edema, fatigue, lightheadedness, palpitations and occasional substernal chest pain. Her past medical history was unremarkable other than mild anemia. On physical exam her respiratory rate was 20 breaths per minute and O2 saturation 94% on room air by pulse oximetry. There was jugular venous distention at 12 cm, 2+ bilateral lower extremity edema, a 5/6 systolic murmur over the left sternal border with a sternal heave. Labwork was unremarkable except for an elevated BNP 657 (normal value < 100 pg/mL).

EKG (Figure 1) showed sinus rhythm with right bundle branch block. A 2-view chest X-ray (Figure 2) showed an enlarged right ventricle as well as dilated pulmonary arteries with no parenchymal infiltrates. CT angiography confirmed CXR findings (Figure 3) and was negative for pulmonary embolism. A 2D echocardiogram revealed a preserved left ventricle ejection fraction with right ventricular pressure of 80 mmHg + CVP, severe tricuspid regurgitation, decreased right ventricular function (as assessed by a Tricuspid annular plane systolic excursion of 10 mm) and flattened septum, suggestive of right ventricular overload (Figure 4). A right heart catheterization was performed revealing pulmonary pressures of 105/45 mmHg with a mean of 63 mmHg, a wedge pressure of 11 mmHg, a pulmonary vascular resistance of 13.19 Wood units and a cardiac output of 3.94 L/min.

The patient was admitted to the intensive care unit to start treatment with intravenous treprostinil and was eventually discharged home with subcutaneous treprostrinil.

Pulmonary arterial hypertension (PAH) is a disease of the pulmonary circulation characterized by a progressive elevation in pulmonary vascular resistance that leads to right ventricular failure and premature death. It is defined as a mean pulmonary artery pressure at rest of 25 mmHg or higher (1). Idiopathic (group 1) PAH requires the exclusion of parenchymal pathology or venous thromboembolic disease as well as a mean wedge pressure less than 15 mmHg. The initial symptoms of PH are the result of an inability to adequately increase cardiac output during exercise which eventually will progress to signs and symptoms of right ventricular failure such as lower extremity edema, syncope/presyncope and chest pain (2,3). Early recognition is of paramount importance to institute adequate treatment.

Roberto J. Bernardo, MD and Carlos Tafich Rios, MD

Internal Medicine Residency, Department of Medicine

University of Arizona, Tucson, AZ

References 

1. McLaughlin VV, Archer SL, Badesch DB, et al. ACCF/AHA 2009 expert consensus document on pulmonary hypertension: a report of the American College of Cardiology Foundation Task Force on Expert Consensus Documents and the American Heart Association: developed in collaboration with the American College. Circulation. 2009. 119:2250-94. [CrossRef] [PubMed] 
2. Runo JR, Loyd JE. Primary pulmonary hypertension. Lancet. 2003. 361:1533-44. [CrossRef] [PubMed]
3. Peacock AJ. Primary pulmonary hypertension. Thorax. 1999;54:1107-18. [CrossRef] [PubMed]

Reference as: Bernardo RJ, Rios CT. Medical image of the week: idiopathic pulmonary artery hypertension. Southwest J Pulm Crit Care. 2014;9(2):101-3. doi: http://dx.doi.org/10.13175/swjpcc101-14   PDF

Medical Image of the Week: Oligemic Lung Field

A Sinister Sign of Acute Pulmonary Embolism? 

Figure 1. Panel A: The chest x-ray showed decreased vascular markings in the right lung field (oligemic right lung field) and reduced prominence of right pulmonary artery.  There is also a small opacity in right lower lung field possibly a pulmonary infarct. Panel B: A Coronal section of the computed tomographic pulmonary angiography showing a large thrombus in the right pulmonary artery (white arrow). Panel C: A 12-lead EKG shows sinus tachycardia, right bundle branch block, deep S wave in lead I (black arrow), deep q wave (orange arrow) and inverted T-wave (green arrow) in lead III. Panel D: A computed tomographic pulmonary angiography showing an enlarged right ventricle (blue arrow) compressing the left ventricle (red arrow).

A 67 year-old woman presented with pleuritic, non-radiating chest pain of sudden onset. She was anxious, diaphoretic, and tachycardic.

The chest radiograph (Figure 1A) showed decreased vascular markings in the entire right lung field (oligemic right lung field) and reduced prominence of the right pulmonary artery.  A small opacity in right lower lung field was suspicious for a pulmonary infarct. A follow-up computed tomographic pulmonary angiography (CTA) showed a large embolus in right pulmonary artery and a smaller embolus in the subsegmental left pulmonary artery (Figure 1B). Twelve-lead electrocardiogram (EKG) findings were notable for a new onset right bundle branch pattern, deep S wave in lead I, with a q-wave and inverted T-wave in Lead III (Figure 1C). A 2-Dimentional echocardiogram showed a massively dilated and hypokinetic right ventricle. The CTA also revealed that the massively distended right ventricle with a deviated interventricular septum was compressing the left ventricle (Figure 1D). Venous duplex study of lower extremities showed an acute thrombosis of the right popliteal vein. 

The patient showed marked clinical improvement after the infusion of tissue plasminogen activator (tPA) and heparin. A chest x-ray obtained 2 days later showed resolution of right sided oligemia. On Day 6, the right bundle branch block had resolved.

Radiographic findings in acute pulmonary embolism (PE) are uncommon. The Westermark sign (oligemia), Hampton hump and prominent central pulmonary artery are infrequently seen in acute PE. Westermark sign of an entire side lung field is rare, sinister sign of a large burden pulmonary embolism.  If identified early, this sign can be invaluable in early recognition and management.

Suman B. Thapamagar MBBS, Ramya Mallareddy MD, Ilya Lantsberg MD

Easton Hospital, Drexel University, Department of Internal Medicine, 250 S. 21st Street, Easton, PA 18042

Reference

1. Agnelli G, Becattini C. Acute pulmonary embolism. N Engl J Med. 2010;363(3):266-74. [CrossRef] [PubMed]

Reference as: Thapamagar SB, Mallareddy R, Lantsberg I. Medical image of the week: oligemic lung field. Southwest J Pulm Crit Care. 2014:8(1):48-9. doi: http://dx.doi.org/10.13175/swjpcc163-13 PDF

Medical Image of the week: Pulmonary Artery Endarterectomy

Figure 1. Organized thrombus with fresh clot removed during pulmonary thromboendarterectomy.

A 34 year-old male was admitted after an episode of syncope.  An echocardiogram revealed moderate enlargement of the RA and RV and an estimated systolic PA pressure of 85 mm Hg.  A perfusion scan showed segmental perfusion defects in the RUL, RML and LLL. He underwent pulmonary thromboendarterectomy with removal of chronic and partially organized thrombus from all lobar and segmental vessels of the right lung, lingula and left lower lobe.  Organized thrombus with some fresh clot is shown.

Nathaniel Reyes, MD and Linda Snyder, MD

Division of Pulmonary, Critical Care, Allergy and Sleep Medicine

Arizona Respiratory Center

University of Arizona

Reference as: Reyes N, Snyder L. Medical image of the week: pulmonary artery endarterectomy. Southwest J Pulm Crit Care 2013;6(1):37. PDF